Racial and gender differences in the relationship between sarcopenia and bone mineral density among older adults

Both sarcopenia and low bone mineral density (BMD) have become public health concerns. We found that presarcopenic and/or sarcopenic individuals were more likely to have lower BMD. And this relationship has race and sex-specific discrepancy.

PURPOSE

The purpose of the study was to investigate the racial and gender differences in the relationship between sarcopenia and BMD among older adults.

METHODS

Totally, 5476 subjects (mean age = 65.7 ± 6.4) of non-Hispanic White (n = 3297), non-Hispanic Black (n = 1265), and non-Hispanic Asian (n = 914) were analyzed. Sarcopenia was defined according to the revised European consensus on definition and diagnosis of sarcopenia (EWGSOP2). General linear model and multivariable linear regression model were used to examine the relationship between sarcopenia and regional/whole body BMD stratified by race and sex. Adjustments were conducted for physiological, behavioral, and disease factors.

RESULTS

Comparing with normal older participants, presarcopenic and sarcopenic elderly were more likely to have lower BMD. Although the difference was not statistically significant in a few sub-groups, among the three racial groups, the strongest association between sarcopenia and BMD was found in non-Hispanic Black people, followed by non-Hispanic White people and non-Hispanic Asian people. In addition, significant differences of BMD across sarcopenia stages were found in more sub-groups in women than in men after adjusting for covariates.

CONCLUSIONS

In this older cohort, sarcopenia is significantly related to low regional/whole-body BMD, and these associations vary by race and sex. Consideration in race and sex is warranted when developing strategies to maintain or minimize BMD loss.

The lncRNA Snhg1-Vps13D vesicle trafficking system promotes memory CD8 T cell establishment via regulating the dual effects of IL-7 signaling

The efficient induction and long-term persistence of pathogen-specific memory CD8 T cells are pivotal to rapidly curb the reinfection. Recent studies indicated that long-noncoding RNAs expression is highly cell- and stage-specific during T cell development and differentiation, suggesting their potential roles in T cell programs. However, the key lncRNAs playing crucial roles in memory CD8 T cell establishment remain to be clarified. Through CD8 T cell subsets profiling of lncRNAs, this study found a key lncRNA-Snhg1 with the conserved naive^hi-effector^lo-memory^hi expression pattern in CD8 T cells of both mice and human, that can promote memory formation while impeding effector CD8 in acute viral infection. Further, Snhg1 was found interacting with the conserved vesicle trafficking protein Vps13D to promote IL-7Rα membrane location specifically. With the deep mechanism probing, the results show Snhg1-Vps13D regulated IL-7 signaling with its dual effects in memory CD8 generation, which not just because of the sustaining role of STAT5-BCL-2 axis for memory survival, but more through the STAT3-TCF1-Blimp1 axis for transcriptional launch program of memory differentiation. Moreover, we performed further study with finding a similar high-low-high expression pattern of human SNHG1/VPS13D/IL7R/TCF7 in CD8 T cell subsets from PBMC samples of the convalescent COVID-19 patients. The central role of Snhg1-Vps13D-IL-7R-TCF1 axis in memory CD8 establishment makes it a potential target for improving the vaccination effects to control the ongoing pandemic.

The lncRNA Snhg1-Vps13D vesicle trafficking system promotes memory CD8 T cell establishment via regulating the dual effects of IL-7 signaling

The efficient induction and long-term persistence of pathogen-specific memory CD8 T cells are pivotal to rapidly curb the reinfection. Recent studies indicated that long-noncoding RNAs expression is highly cell- and stage-specific during T cell development and differentiation, suggesting their potential roles in T cell programs. However, the key lncRNAs playing crucial roles in memory CD8 T cell establishment remain to be clarified. Through CD8 T cell subsets profiling of lncRNAs, this study found a key lncRNA-Snhg1 with the conserved naivehi-effectorlo-memoryhi expression pattern in CD8 T cells of both mice and human, that can promote memory formation while impeding effector CD8 in acute viral infection. Further, Snhg1 was found interacting with the conserved vesicle trafficking protein Vps13D to promote IL-7Rα membrane location specifically. With the deep mechanism probing, the results show Snhg1-Vps13D regulated IL-7 signaling with its dual effects in memory CD8 generation, which not just because of the sustaining role of STAT5-BCL-2 axis for memory survival, but more through the STAT3-TCF1-Blimp1 axis for transcriptional launch program of memory differentiation. Moreover, we performed further study with finding a similar high-low-high expression pattern of human SNHG1/VPS13D/IL7R/TCF7 in CD8 T cell subsets from PBMC samples of the convalescent COVID-19 patients. The central role of Snhg1-Vps13D-IL-7R-TCF1 axis in memory CD8 establishment makes it a potential target for improving the vaccination effects to control the ongoing pandemic.

Perfluorocarbon Protects against Lipopolysaccharide-Induced Apoptosis of Endothelial Cells in Pulmonary Microvessels

This study was aimed to explore the effect and mechanisms of action of perfluorocarbon on LPS-induced apoptosis of pulmonary microvascular endothelial cells (PMVEC) isolated from Sprague-Dawley rats. Apoptosis rates were assessed by flow cytometry. Ultrastructural characteristics of PMVEC were evaluated by transmission electron microscopy. The protein expression of cleaved caspase-3 was measured using Western blotting. LPS significantly increased the level of apoptosis, induced the appearance of ultrastructural changes typical of apoptosis, up-regulated the expression of active caspase-3 protein. These effects of LPS were attenuated by co-administration of perfluorocarbon. These results suggest that perfluorocarbon can attenuate LPS-induced apoptosis of PMVEC by inhibiting TLR-4 signaling and caspase-3 activation.

Abnormal large-scale structural rich club organization in Leber's hereditary optic neuropathy

•

LHON patients suffered large-scale structural network disruption.

•

Non-rich club connections may be more vulnerable in the LHON.

•

Both primary and secondary connectivity damage may coexist in the LHON.

Objective

The purpose of this study was to investigate whether the large-scale structural rich club organization was abnormal in patients with Leber's hereditary optic neuropathy (LHON) using diffusion tensor imaging (DTI), and the associations among disrupted brain structural connectivity, disease duration, and neuro-ophthalmological impairment.

Methods

Nineteen acute, 34 chronic LHON patients, and 36 healthy controls (HC) underwent DTI and neuro-ophthalmological measurements. The brain structural network and rich club organization were constructed based on deterministic fiber tracking at the individual level. Then intergroup differences among the acute, chronic LHON patients and healthy controls (HC) in three types of structural connections, including rich club, feeder, and local ones, were compared. Network-based Statistics (NBS) was also used to test the intergroup connectivity differences for each fiber. Several linear and nonlinear curve fit models were applied to explore the associations among large-scale brain structural connectivity, disease duration, and neuro-ophthalmological metrics.

Results

Compared to the HC, both the acute and chronic LHON patients had consistently significantly lower fractional anisotropy (FA) and higher radial diffusion (RD) for feeder connections (p < 0.05, FDR correction). Acute LHON patients had significantly lower FA and higher RD for local connections (p < 0.05, FDR correction). There was no significant difference in large-scale brain structural connectivity between acute and chronic LHON (p > 0.05, FDR correction). NBS also identified reduced FA of three feeder connections and five local ones linking visual, auditory, and basal ganglia areas in LHON patients (p < 0.05, FDR correction). No structural connections showed linear or nonlinear association with either disease duration or neuro-ophthalmological indicators (p > 0.05, FDR correction). A significant negative correlation was shown between the retinal nerve fiber layer (RNFL) thickness and disease duration (p < 0.05, FDR correction).

Conclusions

Abnormal rich club organization of the structural network was identified in both the acute and chronic LHON. Furthermore, our findings suggest the coexistence of both primary and secondary connectivity damage in the LHON.

Comparison of diffusion MRI and CLARITY fiber orientation estimates in both gray and white matter regions of human and primate brain

Diffusion MRI (dMRI) represents one of the few methods for mapping brain fiber orientations non-invasively. Unfortunately, dMRI fiber mapping is an indirect method that relies on inference from measured diffusion patterns. Comparing dMRI results with other modalities is a way to improve the interpretation of dMRI data and help advance dMRI technologies. Here, we present methods for comparing dMRI fiber orientation estimates with optical imaging of fluorescently labeled neurofilaments and vasculature in 3D human and primate brain tissue cuboids cleared using CLARITY. The recent advancements in tissue clearing provide a new opportunity to histologically map fibers projecting in 3D, which represents a captivating complement to dMRI measurements. In this work, we demonstrate the capability to directly compare dMRI and CLARITY in the same human brain tissue and assess multiple approaches for extracting fiber orientation estimates from CLARITY data. We estimate the three-dimensional neuronal fiber and vasculature orientations from neurofilament and vasculature stained CLARITY images by calculating the tertiary eigenvector of structure tensors. We then extend CLARITY orientation estimates to an orientation distribution function (ODF) formalism by summing multiple sub-voxel structure tensor orientation estimates. In a sample containing part of the human thalamus, there is a mean angular difference of 19o±15o between the primary eigenvectors of the dMRI tensors and the tertiary eigenvectors from the CLARITY neurofilament stain. We also demonstrate evidence that vascular compartments do not affect the dMRI orientation estimates by showing an apparent lack of correspondence (mean angular difference = 49o±23o) between the orientation of the dMRI tensors and the structure tensors in the vasculature stained CLARITY images. In a macaque brain dataset, we examine how the CLARITY feature extraction depends on the chosen feature extraction parameters. By varying the volume of tissue over which the structure tensor estimates are derived, we show that orientation estimates are noisier with more spurious ODF peaks for sub-voxels below 30 µm3 and that, for our data, the optimal gray matter sub-voxel size is between 62.5 µm3 and 125 µm3. The example experiments presented here represent an important advancement towards robust multi-modal MRI-CLARITY comparisons.

Flame-Retardant Performance of Epoxy Resin Composites with SiO2 Nanoparticles and Phenethyl-Bridged DOPO Derivative

Flame retardancy of epoxy resin (EP) plays a vital role in its applications. When inorganic nanomaterials form inorganic/organic nanocomposites, they exhibit special flame-retardant effects. In this study, EP nanocomposites were prepared by the incorporation of SiO2 nanoparticles and phenethyl-bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative (DiDOPO), and the synergistic effects of SiO2 nanoparticles and DiDOPO on the flame-retardant performance of EP were discussed. Results indicated that the introduction of only 15 wt % SiO2 and 5 wt % DiDOPO in EP leads to the increase in the limiting oxygen index from 21.8 to 30.2%, and the nanocomposites achieve the UL-94 V-0 rating. Thermogravimetric analysis revealed that char yield increases with the increase in the SiO2 content of the nanocomposites and that an increased amount of thermally stable carbonaceous char is formed. SiO2 nanoparticles can improve the thermal stability and mechanical performance of EP; hence, the nanoparticles can serve as an efficient adjuvant for the DiDOPO/EP flame-retardant system.

Caspofungin combined with TMP/SMZ as a first-line therapy for moderate-to-severe PCP in patients with human immunodeficiency virus infection

OBJECTIVES

The effectiveness of trimethoprim/sulfamethoxazole (TMP/SMZ) for pneumocystis pneumonia (PCP) is limited with adverse events. Caspofungin, by inhibiting the cyst form of Pneumocystis jirovecii, may be an alternative therapy for PCP. However, the availability of clinical data about caspofungin combined with TMP/SMZ in the treatment of PCP in HIV-infected patients is limited. Thus, we aimed to examine the clinical effectiveness and safety of caspofungin combined with TMP/SMZ as a first-line therapy for moderate-to-severe PCP in HIV-infected patients.

METHODS

From January 2017 to December 2019, data of HIV-infected patients with moderate-to-severe PCP who received either TMP/SMZ alone or caspofungin combined with TMP/SMZ as first-line therapy were retrospectively reviewed to assess the effectiveness and safety of each regimen. The Kaplan-Meier curve and log-rank test were used for survival analysis.

RESULTS

A total of 278 patients met the criteria. The overall positive response rate of PCP treatment was 48.92%, and the overall all-cause in-hospital mortality rate was 33.09%. Patients who received combination therapy consisting of caspofungin and TMP/SMZ had a better positive response rate (59.44% vs. 37.78%, P < 0.001) and lower all-cause in-hospital mortality rate (24.48% vs. 42.22%, P = 0.003). Also, patients who received combination therapy had higher survival rate during a hospital stay (75.52% vs. 57.78%, P = 0.004), and those who received longer combination therapy were more likely to have higher survival rate (P = 0.042). We found that age (P = 0.019), CD4 cell count (P = 0.001) and therapeutic regimen (P = 0.002) were significant risk factors for all-cause in-hospital mortality rate in univariate analysis. In multivariate analysis, only CD4 cell count and therapeutic regimen were statistically significant factors associated with all-cause in-hospital mortality rate. Patients with a CD4 count of > 30 cells/µL and patients who received combination therapy consisting of caspofungin and TMP/SMZ were more likely to survive from PCP (P = 0.011 and P = 0.002, respectively). There were no additional severe adverse events caused by adding caspofungin.

CONCLUSIONS

For HIV-infected patients with moderate-to-severe PCP, combination therapy with caspofungin and TMP/SMZ is an effective and promising first-line therapy with no greater number of adverse events compared with TMP/SMZ monotherapy. Patients who received caspofungin had better positive response rates and lower all-cause in-hospital mortality rates. Also, we recommend early initiation of caspofungin.

Genome-wide identification and analysis of NPR family genes in Brassica juncea var. tumida

Nonexpressor of pathogenesis-related (NPR) genes are bona fide transcription cofactors in the signal transduction pathway of salicylic acid (SA) and play critical regulatory roles in plant immunity. However, the NPR family genes in Brassica juncea var. tumida have not yet been comprehensively identified and analyzed as of yet. In the present study, NPR genes in B. juncea var. tumida seedlings were identified, and the tissue-specific expression patterns of NPR genes in the seedling were analyzed under salt stress (200 mM) treatment and infection by Plasmodiophora brassicae. A total of 19 NPR family genes clustering into six separate groups were identified in the genome of B. juncea var. tumida. These BjuNPR family genes were located in 11 of 18 chromosomes of B. juncea var. tumida and each possessed 1-5 exons. The BjuNPR family members had similar protein structures and conserved motifs. The BjuNPR genes exhibited tissue-specific expression patterns in the root, stem, leaf, flower and pod. Some BjuNPR genes were sensitive to salt stress and showed up-regulated or down-regulated expression patterns and most BjuNPR genes were up-regulated upon infection by P. brassicae. This study provides a foundation for further research into BjuNPR genes regulation in plant growth, development, and abiotic stress tolerance.

Cascaded Fabry-Perot interferometer-regenerated fiber Bragg grating structure for temperature-strain measurement under extreme temperature conditions

We demonstrated an optical fiber sensor based on a cascaded fiber Fabry-Perot interferometer (FPI)-regenerated fiber Bragg grating (RFBG) for simultaneous measurement of temperature and strain under high temperature environments. The FPI is manufactured from a ∼74 µm long hollow core silica tube (HCST) sandwiched between two single mode fibers (SMFs). The RFBG is inscribed in one of the SMF arms which is embedded inside an alundum tube, making it insensitive to the applied strain on the entire fiber sensor, just in case the temperature and strain recovery process are described using the strain-free RFBG instead of a characteristic due-parameter matrix. This feature is intended for thermal compensation for the FPI structure that is sensitive to both temperature and strain. In the characterization tests, the proposed device has exhibited a temperature sensitivity ∼ 18.01 pm/°C in the range of 100 °C - 1000 °C and excellent linear response to strain in the range of 300 °C - 1000 °C. The measured strain sensitivity is as high as ∼ 2.17 pm/µɛ for a detection range from 0 µɛ to 450 µɛ at 800 °C, which is ∼ 1.5 times that of a FPI-RFBG without the alundum tube.

Genomic signatures and candidate genes of lint yield and fibre quality improvement in Upland cotton in Xinjiang

Xinjiang has been the largest and highest yield cotton production region not only in China, but also in the world. Improvements in Upland cotton cultivars in Xinjiang have occurred via pedigree selection and/or crossing of elite alleles from the former Soviet Union and other cotton producing regions of China. But it is unclear how genomic constitutions from foundation parents have been selected and inherited. Here, we deep-sequenced seven historic foundation parents, comprising four cultivars introduced from the former Soviet Union (108Ф, C1470, 611Б and KK1543) and three from United States and Africa (DPL15, STV2B and UGDM), and re-sequenced sixty-nine Xinjiang modern cultivars. Phylogenetic analysis of more than 2 million high-quality single nucleotide polymorphisms allowed their classification two groups, suggesting that Xinjiang Upland cotton cultivars were not only spawned from 108Ф, C1470, 611Б and KK1543, but also had a close kinship with DPL15, STV2B and UGDM. Notably, identity-by-descent (IBD) tracking demonstrated that the former Soviet Union cultivars have made a huge contribution to modern cultivar improvement in Xinjiang. A total of 156 selective sweeps were identified. Among them, apoptosis-antagonizing transcription factor gene (GhAATF1) and mitochondrial transcription termination factor family protein gene (GhmTERF1) were highly involved in the determination of lint percentage. Additionally, the auxin response factor gene (GhARF3) located in inherited IBD segments from 108Ф and 611Б was highly correlated with fibre quality. These results provide an insight into the genomics of artificial selection for improving cotton production and facilitate next-generation precision breeding of cotton and other crops.

Pleiotropic loci underlying bone mineral density and bone size identified by a bivariate genome-wide association analysis

Aiming to identify pleiotropic genomic loci for bone mineral density and bone size, we performed a bivariate GWAS in five discovery samples and replicated in two large-scale samples. We identified 2 novel loci at 2q37.1 and 6q26. Our findings provide insight into common genetic architecture underlying both traits.

INTRODUCTION

Bone mineral density (BMD) and bone size (BS) are two important factors that contribute to the development of osteoporosis and osteoporotic fracture. Both BMD and BS are highly heritable and they are genetically correlated. In this study, we aim to identify pleiotropic loci associated with BMD and BS.

METHODS

We conducted a bivariate genome-wide association (GWA) analysis of hip BMD and hip BS in 6180 participants from 5 samples, followed by in silico replication in the UK Biobank study of BMD (N = 426,824) and the deCODE study of BS (N = 28,954), respectively.

RESULTS

SNPs from 2 genomic loci were significant at the genome-wide significance (GWS) level (p lt; 5 × 10^-8) in the discovery samples and were successfully replicated in the replication samples (2q37.1, lead SNP rs7575512, discovery p = 1.49 × 10^-10, replication p = 0.05; 6q26, lead SNP rs1040724, discovery p = 1.95 × 10^-8, replication p = 0.03). Functional annotations suggested functional relevance of the identified variants to bone development.

CONCLUSION

Our findings provide insight into the common genetic architecture underlying BMD and BS, and enhance our understanding of the potential mechanism of osteoporosis fracture.

Evaluation of Ultrafast Wave-CAIPI MPRAGE for Visual Grading and Automated Measurement of Brain Tissue Volume

BACKGROUND AND PURPOSE

Volumetric brain MR imaging typically has long acquisition times. We sought to evaluate an ultrafast MPRAGE sequence based on Wave-CAIPI (Wave-MPRAGE) compared with standard MPRAGE for evaluation of regional brain tissue volumes.

MATERIALS AND METHODS

We performed scan-rescan experiments in 10 healthy volunteers to evaluate the intraindividual variability of the brain volumes measured using the standard and Wave-MPRAGE sequences. We then evaluated 43 consecutive patients undergoing brain MR imaging. Patients underwent 3T brain MR imaging, including a standard MPRAGE sequence (acceleration factor [R] = 2, acquisition time [TA] = 5.2 minutes) and an ultrafast Wave-MPRAGE sequence (R = 9, TA = 1.15 minutes for the 32-channel coil; R = 6, TA = 1.75 minutes for the 20-channel coil). Automated segmentation of regional brain volume was performed. Two radiologists evaluated regional brain atrophy using semiquantitative visual rating scales.

RESULTS

The mean absolute symmetrized percent change in the healthy volunteers participating in the scan-rescan experiments was not statistically different in any brain region for both the standard and Wave-MPRAGE sequences. In the patients undergoing evaluation for neurodegenerative disease, the Dice coefficient of similarity between volumetric measurements obtained from standard and Wave-MPRAGE ranged from 0.86 to 0.95. Similarly, for all regions, the absolute symmetrized percent change for brain volume and cortical thickness showed <6% difference between the 2 sequences. In the semiquantitative visual comparison, the differences between the 2 radiologists' scores were not clinically or statistically significant.

CONCLUSIONS

Brain volumes estimated using ultrafast Wave-MPRAGE show low intraindividual variability and are comparable with those estimated using standard MPRAGE in patients undergoing clinical evaluation for suspected neurodegenerative disease.

Hypomethylation of Notch1 DNA is associated with the occurrence of uveitis

Uveitis is a serious intra-ocular inflammatory disease that can lead to visual impairment even blindness worldwide. Notch signaling can regulate the differentiation of naive CD4⁺ T cells, influencing the development of uveitis. DNA methylation is closely related to the autoimmune diseases. In this study, we measured the Notch1 DNA methylation level, determined the Notch1 and related DNA methylases mRNA expression and evaluated the ratio of T helper type 17 regulatory T cell (Th17/T_reg ) in peripheral blood mononuclear cells (PBMCs) from uveitis patients and normal control subjects; we also tested the levels of relevant inflammatory cytokines in serum from the participants. Results indicated that compared with those in normal control individuals, the expression of ten-eleven translocation 2 (TET2) and Notch1 mRNA is elevated in uveitis patients, whereas the methylation level in Notch1 DNA promotor region [-842 ~ -646 base pairs (bp)] is down-regulated, and is unrelated to anatomical location. Moreover, the Th17/T_reg ratio is up-regulated in PBMCs from uveitis patients, accompanied by the elevated levels of proinflammatory cytokines [e.g. interleukin (IL)-2, IL-6, IL-17 and interferon (IFN)-γ] in serum from uveitis patients. These findings suggest that the over-expression of TET2 DNA demethylase may lead to hypomethylation of Notch1, activate the Notch1 signaling, induce naive CD4⁺ T cells to differentiate theTh17 subset and thus disturb the balance of the Th17/T_reg ratio in uveitis patients. Overall, hypomethylation of Notch1 DNA is closely associated with the occurrence of uveitis. Our study preliminarily reveals the underlying mechanism for the occurrence of uveitis related to the hypomethylation of Notch1 DNA, providing a novel therapeutic strategy against uveitis in clinical practice.

Non-invasive prediction of fetal growth restriction by whole-genome promoter profiling of maternal plasma DNA: a nested case-control study

Objective

To predict fetal growth restriction (FGR) by whole‐genome promoter profiling of maternal plasma.

Design

Nested case–control study.

Setting

Hospital‐based.

Population or Sample

810 pregnancies: 162 FGR cases and 648 controls.

Methods

We identified gene promoters with a nucleosome footprint that differed between FGR cases and controls based on maternal plasma cell‐free DNA (cfDNA) nucleosome profiling. Optimal classifiers were developed using support vector machine (SVM) and logistic regression (LR) models.

Main outcome measures

Genes with differential coverages in promoter regions through the low‐coverage whole‐genome sequencing data analysis among FGR cases and controls. Receiver operating characteristic (ROC) analysis (area under the curve [AUC], accuracy, sensitivity and specificity) was used to evaluate the performance of classifiers.

Results

Through the low‐coverage whole‐genome sequencing data analysis of FGR cases and controls, genes with significantly differential DNA coverage at promoter regions (−1000 to +1000 bp of transcription start sites) were identified. The non‐invasive ‘FGR classifier 1’ (C_FGR1) had the highest classification performance (AUC, 0.803; 95% CI 0.767–0.839; accuracy, 83.2%) was developed based on 14 genes with differential promoter coverage using a support vector machine.

Conclusions

A promising FGR prediction method was successfully developed for assessing the risk of FGR at an early gestational age based on maternal plasma cfDNA nucleosome profiling.

Tweetable abstract

A promising FGR prediction method was successfully developed, based on maternal plasma cfDNA nucleosome profiling.

A promising FGR prediction method was successfully developed, based on maternal plasma cfDNA nucleosome profiling.

Intranasal dexmedetomidine is an effective sedative agent for electroencephalography in children

BACKGROUND

Intranasal dexmedetomidine (DEX), as a novel sedation method, has been used in many clinical examinations of infants and children. However, the safety and efficacy of this method for electroencephalography (EEG) in children is limited. In this study, we performed a large-scale clinical case analysis of patients who received this sedation method. The purpose of this study was to evaluate the safety and efficacy of intranasal DEX for sedation in children during EEG.

METHODS

This was a retrospective study. The inclusion criteria were children who underwent EEG from October 2016 to October 2018 at the Children's Hospital affiliated with Chongqing Medical University. All the children received 2.5 μg·kg^- 1 of intranasal DEX for sedation during the procedure. We used the Modified Observer Assessment of Alertness/Sedation Scale (MOAA/S) and the Modified Aldrete score (MAS) to evaluate the effects of the treatment on sedation and resuscitation. The sex, age, weight, American Society of Anesthesiologists physical status (ASAPS), vital signs, sedation onset and recovery times, sedation success rate, and adverse patient events were recorded.

RESULTS

A total of 3475 cases were collected and analysed in this study. The success rate of the initial dose was 87.0% (3024/3475 cases), and the success rate of intranasal sedation rescue was 60.8% (274/451 cases). The median sedation onset time was 19 mins (IQR: 17-22 min), and the sedation recovery time was 41 mins (IQR: 36-47 min). The total incidence of adverse events was 0.95% (33/3475 cases), and no serious adverse events occurred.

CONCLUSIONS

Intranasal DEX (2.5 μg·kg^- 1) can be safely and effectively used for EEG sedation in children.

The 95% effective dose of intranasal dexmedetomidine sedation for pulmonary function testing in children aged 1-3 years: A biased coin design up-and-down sequential method

STUDY OBJECTIVE

Intranasal dexmedetomidine (DEX) can provide adequate sedation during short examinations in children. However, we found no data regarding the 95% effective dose (ED₉₅) of intranasal DEX for children's pulmonary function testing (PFT).

DESIGN

Prospective study and a biased coin design up-and-down sequential method.

SETTING

Sedation center of Children's Hospital of Chongqing Medical University.

PATIENTS

Children aged 1-3 years undergoing pulmonary function testing.

INTERVENTION

The dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg^-1.

MEASUREMENTS

Children aged 1-3 years who received pulmonary function testing were involved in this dose-finding trial. Intranasal DEX started at a dose of 2 μg∙kg^-1 on the first patient. The dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg^-1. The sedation was assessed by the Modified Observer Assessment of Alertness and Sedation (MOAA/S) scale, and recovery was assessed by the modified Aldrete recovery score. The ED₉₅ was calculated using isotonic regression. Other variables, including the sedation onset time, examination time, wake-up time, blood pressure (BP), heart rate (HR), respiratory rate (RR), and oxyhaemoglobin desaturation (SpO₂), were recorded. Adverse events such as hypotension, bradycardia, respiration depression, oxyhaemoglobin desaturation, regurgitation and vomiting were recorded.

MAIN RESULTS

A total of 68 children were enrolled for the study; 62 children had successful sedation, and 6 had failed sedation. The ED₉₅ of intranasal DEX was estimated to be 2.64 μg∙kg^-1 [95% confidence interval (CI), 2.49-2.87 μg∙kg^-1]. The sedation onset time for all patients was 15.0 (12.3-19.0) min. The sedation onset time of successful sedation patients was 15.0 (12.0-19.0) min, the sedation onset time of failed sedation patients was 16.0 (15.0-27.8) min, the examination time was 8 (7-10) min, and the wake-up time was 40 (35-43) min. There were no adverse events during the whole procedure.

CONCLUSION

The ED₉₅ of intranasal DEX sedation in children aged 1-3 years undergoing PFT was 2.64 μg∙kg^-1.

Phosphoprotein Gene of Wild-Type Rabies Virus Plays a Role in Limiting Viral Pathogenicity and Lowering the Enhancement of BBB Permeability

Enhancement of blood–brain barrier (BBB) permeability is necessary for clearing virus in the central nervous system (CNS). It has been reported that only laboratory-attenuated rabies virus (RABV) induces inflammatory response to lead BBB transient breakdown rather than wild-type (wt) strains. As a component of ribonucleoprotein (RNP), phosphoprotein (P) of RABV plays a key role in viral replication and pathogenicity. To our knowledge, the function of RABV P gene during RABV invasion was unclear so far. In order to determine the role of RABV P gene during RABV infection, we evaluated the BBB permeability in vivo after infection with wt RABV strain (GD-SH-01), a lab-attenuated RABV strain (HEP-Flury), and a chimeric RABV strain (rHEP-SH-P) whose P gene cloned from GD-SH-01 was expressed in the genomic backbone of HEP-Flury. We found that rHEP-SH-P caused less enhancement of BBB permeability and was less pathogenic to adult mice than GD-SH-01 and HEP-Flury. In an effort to investigate the mechanism, we found that the replication of rHEP-SH-P has been limited due to the suppressed P protein expression and induced less response to maintain BBB integrity. Our data indicated that the P gene of wt RABV was a potential determinant in hampering viral replication in vivo, which kept BBB integrity. These findings provided an important foundation for understanding the viral invasion and development of novel vaccine.